In some instances, multiple access networks are available in order to support communications with a mobile terminal or other communications device. For example, system architecture evolution (SAE) introduces the evolved packet core (EPC) network that accommodates both third generation partnership project (3GPP) access networks, such global system for mobile communications (GSM)/enhanced data rate for global evolution (EDGE) radio access networks (GERANs), universal mobile telecommunications system (UMTS) terrestrial radio access networks (UTRANs), high speed packet access (HSPA) networks and evolved UTRANs (E-UTRANs), as well as non-3GPP access networks, such as wireless local area networks (WLANs). In SAE, an access network discovery and selection function (ANDSF) is introduced to allow a network operator to steer or control the flow of communications to and from a mobile terminal over different access networks in a controlled fashion based upon ANDSF policies. In this regard, the ANDSF policies include routing policies that instruct the mobile terminal as to which access network to utilize for certain types of network communications. For example, the ANDSF policy may instruct the mobile terminal to utilize WLAN access for internet browsing and to utilize a 3GPP access network for all other types of network communications.
In some instances, non-seamless WLAN offloading may be supported. For example, the 3GPP specification provides support for non-seamless WLAN offloading. In regards to non-seamless WLAN offloading, the session of the mobile terminal that is conducted over the WLAN is not anchored in the core network of the network operator, but, instead, the WLAN session is conducted without traversing the gateway of any cellular operator.
In one implementation, split-user equipment (UE) is provided that includes both a terminal equipment and a mobile terminal The terminal equipment may be a computer, such as a laptop computer or the like, or any other type of computing device that implements an internet protocol (IP) connectivity stack, e.g., a transmission control protocol (TCP)/IP stack. While the mobile terminal may be a mobile telephone, a portable digital assistant (PDA) or other type of mobile terminal The terminal equipment and the mobile terminal may be connected, such as by means of a wireless connection, such that the mobile terminal can provide some of the functions of the mobile terminal for the terminal equipment.
In a split UE scenario, the terminal equipment and the mobile terminal may communicate with different access networks. For example, the terminal equipment may communicate with a WLAN, while the mobile terminal communicates with a cellular network. Although the mobile terminal may include the ANDSF and may consequently interact with access networks based upon the ANDSF policies, the terminal equipment does not include the ANDSF and, as such, does not support the ANDSF policies. however, the terminal equipment may still receive other routing information, such as internet engineering task force (IETF) routing and router information, such as defined by REF 4191, via the connection that the terminal equipment has established with an access network, such as the WLAN. In the split UE scenario, the terminal equipment may directly communicate with some access networks, such as WLANs, but the mobile terminal may provide the connection to other access networks, such as the cellular access networka. Thus, the mobile terminal in a split UE scenario may transparently bridge the connection from the terminal equipment to the radio networks.
The routing information may not be coordinated. For example, the ANDSF routing policy and the IETF routing and router information may not be coordinated. As such, the behavior of the split UE may differ from that expected by the cellular operator that expects that the ANDSF routing policies will steer or direct the communications from the split UE. Absent coordination, however, the IETF routing and router information may sometime cause the split UE to establish communications with the various access networks in a different manner than that directed by the ANDSF routing policies. By way of example, the ANDSF routing policy may indicate, pursuant to the preference of the cellular operator, that all internet traffic is to be routed through the WLAN and the remainder of the traffic is to be routed over 3GPP access network(s). If, however, the IETF routing and router information, such as the router advertisements/default router preferences, indicates that a router reachable over the WLAN has a lower preference than a router reachable over a 3GPP access network, the operating system of the terminal equipment may route the internet traffic to the 3GPP access network due to its higher default router preference and not the WLAN as indicated by the ANDSF routing policies. In this regard, although the mobile terminal may include the ANDSF routing policies, the terminal equipment does not include the ANDSF routing policies and, as a result, may rely upon other routing information, such as the IETF router and routing information, to direct the traffic to different access networks than those contemplated by the ANDSF routing policies. By steering the traffic in a manner different than that defined by the ANDSF routing policies and, as a result, different than that expected by the network operator, the user of the split UE may have a less desirable and/or more expensive user experience.